Intestinal Na+/glucose cotransporter-mediated transport of glucose conjugate formed from disaccharide conjugate.
Intestinal absorption of beta-disaccharide (cellobiose, maltose and lactose) conjugates of p-nitrophenol (p-nitrophenyl beta-disaccharide) were examined in terms of the hydrolysis of disaccharide conjugate to monosaccharide conjugate and the transport of monosaccharide conjugate by Na+/glucose transport carrier (SGLT1). beta-Cellobioside, beta-maltoside and beta-lactoside of p-nitrophenol (p-NP) were hydrolyzed to p-nitrophenyl beta-glucoside (p-NPbeta glc) on the mucosal side, and p-NPbeta glc appeared on the serosal side. Although p-NP beta-disaccharide, p-NP and p-NP glucuronide also appeared on the serosal side, their amounts were much lower than that of p-NPbeta glc. The amount of p-NPbeta glc transported to the serosal side was decreased in the presence of phloridzin (transport inhibitor of SGLT1) and in the absence of Na+ (a cosubstrate of SGLT1), indicating that p-NPbeta glc was formed from p-NP beta-disaccharide on the mucosal side and transported to the serosal side by SGLT1. Furthermore, the absorption clearance of p-NPbeta glc, which was formed from p-NP beta-cellobioside and p-NP beta-lactoside by lactase-phloridzin hydrolase (LPH), was much higher than that of p-NPbeta glc itself, although the absorption clearance of p-NPbeta glc, which was formed from p-NP beta-maltoside by maltase was similar to that of p-NPbeta glc itself. These results indicated that p-NPbeta glc was transported by the vectorial cooperation of SGLT1 with LPH from mucosal p-NP beta-cellobioside or p-NP beta-lactoside.
Mizuma
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T
Department of Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Japan.
Awazu
S
S
D000818:Animals; D001692:Biological Transport; D004187:Disaccharides / Q000378:metabolism*; D005960:Glucosides / Q000378:metabolism*; D005965:Glucuronates / Q000032:analysis / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D006027:Glycosides / Q000378:metabolism; D007408:Intestinal Absorption / Q000502:physiology; D007421:Intestine, Small / Q000378:metabolism*; D010694:Lactase-Phlorizin Hydrolase / Q000378:metabolism; D008297:Male; D008320:Maltose / Q000031:analogs & derivatives / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism*; D015394:Molecular Structure; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009596:Nitrophenols / Q000032:analysis / Q000378:metabolism; D010695:Phlorhizin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D051269:Sodium-Glucose Transporter 1
D004187:Disaccharides; D005960:Glucosides; D005965:Glucuronates; D006027:Glycosides; D008562:Membrane Glycoproteins; D009004:Monosaccharide Transport Proteins; D009596:Nitrophenols; C495676:Slc5a1 protein, rat; D051269:Sodium-Glucose Transporter 1; C002730:4-nitrophenylglucuronide; C029976:4-aminophenyl beta-lactoside; C025193:4-nitrophenyl beta-D-glucoside; C034170:4-nitrophenyl beta-cellobioside; D008320:Maltose; D010695:Phlorhizin; D006026:Glycoside Hydrolases; D010694:Lactase-Phlorizin Hydrolase; C024836:4-nitrophenol